JPH0532668Y2 - - Google Patents

Description

[Detailed description of the invention] A. Field of industrial application The invention is a fluid that is configured to be able to transmit rotational torque by utilizing the viscosity of a working fluid, and is used in overhead traveling cranes, swing devices, trolley drive devices, etc. Concerning improvements to joints.

B. Prior Art In fluid couplings that use viscous fluids, when the fluid is heated internally or by an external heat source, its viscosity decreases and the torque that can be transmitted decreases due to heat loss caused by disc slippage. do. However, the reduction in torque can be compensated for by increasing the rotational speed difference between the input and output shafts or by decreasing the spacing between the discs.

However, since it is impractical to increase the difference in rotational speed between the input shaft and the output shaft, a method of reducing the spacing between the disks is generally used.

As such a fluid coupling, Japanese Patent Application Laid-Open No. 58-152941
The technology of "fluid coupling" was disclosed in the publication.
As shown in Figure 10, this consists of an input shaft connected to a driving power source, a sealed rotary casing that surrounds the input shaft so as to be rotatable relative to the input shaft and is filled with viscous fluid, and an output side of the casing. The output shaft connecting portion is provided coaxially with the input shaft, and a plurality of drive disks 6 are provided on the outer peripheral surface of the input shaft so as to be slidable in the axial direction at appropriate intervals. Donut-shaped driven disks 7 are provided on the inner circumferential surface of the casing so as to be slidable in the axial direction and alternately overlap the plurality of drive disks 6 with a slight spacing therebetween, and steel balls 8 are provided on the output side of the casing. A tapered surface is provided to generate a pressing force in the axial direction by utilizing the centrifugal force during rotation, and the steel ball moves toward the outer periphery and applies a pressing force to the driven disk along the tapered surface. This is to prevent a decrease in the transmitted torque by reducing the distance between the two. (Example 1) Furthermore, as described in Japanese Patent Application Laid-open No. 62-9033, the spacing piece is configured as a tension spring 6', and the thin plate 5 is formed with at least one object 8 that deforms significantly depending on the temperature. , 9, or the spacing piece 6 itself consists of such an object, the thin plate 5 having an axially elastic support 7,
The technology of liquid friction clutches is known in which the body which deforms significantly as a function of temperature is an approximately conical bimetallic ring 6, or an expandable material element 8, or a compression spring 9 made of a shape memory alloy. It was hot. (Case 2) Example 2 Furthermore, in the "clutch device equipped with a viscous joint" described in Japanese Patent Application Laid-Open No. 57-204320, the viscosity in the viscous fluid chamber B increases as the rotational speed of the input rotor 10 increases. A viscous joint is disclosed that includes a torque transmission rate changing device D that changes the positional relationship between input side rotary plates 19, 20 and output side rotary plates 22, 23 so that the torque transmission rate due to viscous resistance of fluid is increased. Ta. (Case 3) C. Problem that the invention aims to solve In the above conventional technology, in Case 1, the steel ball 8 moves toward the outer circumference due to the centrifugal force generated as the rotation speed of the input shaft increases, and the steel ball 8 moves along the tapered surface. Since it applies a pressing force to the driven disk and reduces the distance between the disks, it is possible to prevent a decrease in the transmitted torque even if the viscous resistance decreases due to an increase in the rotation speed of the input shaft. Since the spacing between the disks is not automatically adjusted in response to increases in fluid temperature due to number fluctuations or other causes, the torque fluctuation rate during driving is large and stability is lacking. Moreover, since there is no spacer between the driving disk 6 and the driven disk, there is a possibility that the two will rub against each other and wear out.
There were drawbacks such as heat generation and an abnormally high fluid temperature.

Furthermore, in case 2, the spacing piece 6 is constructed as a tension spring 6', in particular an annular disk spring, and the thin plate 5 is formed by a wax element 8 as an expansion material element or a compression spring 9 made of a shape memory alloy.
Alternatively, since the spacing piece 6 is axially supported or constructed as a conical bimetallic ring, and the thin plates 5 have an axially elastic support 7, the bimetallic ring first has a spacing width between the thin plates 5. When the temperature of the viscous liquid increases, the bimetal ring itself becomes flat, and the width of the gap between the thin plates 5 decreases due to the action of the axial elastic support section 7.
In addition to the action of the bimetal ring alone, the action of the axial elastic support portion 7 is required, and the spacing between the thin plates 5 can only be adjusted by the action of both.

Since the axial elastic support part 7 does not act in response to changes in the temperature of the liquid, and is pressed from one side of the bimetal ring, the spacing between the thin plates 5 can be adjusted to an even and optimal spacing. This results in variations in the interval width, a large torque fluctuation rate during driving, and a lack of stability. Further, since the bimetal rings are not individually arranged between adjacent thin plates, they have a poor function as a spacer, and there is a risk that the thin plates 5 will rub and wear out.

In addition, in case 3, as the rotational speed of the input-side rotating body 10 increases and the centrifugal force acting on each pressing ball 27 increases, each pressing ball 27 resists the elastic force of each compression spring S and the outer circumference of the pressing ball 27 increases. Since it moves to the side, the distance between each of the input-side rotating bodies 19, 20 and each of the output-side rotating bodies 22, 23 becomes smaller, so that the torque transmission rate due to the viscous resistance of the viscous fluid increases. Therefore, the viscous joint A can absorb and alleviate sudden fluctuations in the rotation speed and torque, but as in case 1, the viscous joint A is sensitive to the temperature rise of the fluid due to fluctuations in the input shaft rotation speed and other causes. Since the spacing between the disks was not automatically adjusted, the torque fluctuation rate during driving was large and stability was lacking.

D. Means for Solving the Problems In view of the above-mentioned problems of the prior art, the present invention prevents a decrease in the transmitted torque due to an increase in the rotational speed of the input shaft, has a small torque fluctuation rate during driving, and has a drive disc. The purpose is to provide a fluid coupling that prevents friction between the drive disk and the driven disk, and its configuration includes an input shaft connected to a drive power source and a fluid coupling that surrounds the input shaft so as to be able to rotate relative to the input shaft. Moreover, it consists of a rotary casing in a sealed state filled with a viscous fluid inside, and an output shaft provided coaxially with the input shaft on the output side of the casing, and a plurality of drive disks are provided on the outer peripheral surface of the input shaft. The drive disks are provided so as to be slidable in the axial direction at appropriate intervals, and donut-shaped driven disks are provided on the inner circumferential surface of the casing to alternately overlap with the plurality of driving disks at slight intervals. In a fluid coupling that is movably provided, the distance between adjacent driven disks is normally maintained, and the distance between the driven disks is reduced by shortening the spring length at a desired temperature. a compression coil spring made of a shape memory alloy that can be shortened; and a cylindrical body that is fixed to the driven disk and has a thickness larger than the thickness of the drive disk and that allows the compression coil spring to be inserted therein. This is because a spacer is provided.

E. Function The fluid coupling of the present invention supports the driven disk so as to be slidable in the axial direction on the inner peripheral surface of the casing,
By disposing a compression coil spring made of a shape memory alloy and a spacer between the driven disks, the compression coil springs, which have undergone shape memory heat treatment, maintain an equal distance between adjacent driven disks under normal conditions, and the fluid As the temperature rises to reach the desired temperature, its compression coil spring stiffens and shortens its coil length, applying a tensile force to each disk and uniformly reducing the spacing between each disk to the spacer dimensions, thereby increasing the temperature. Even if the viscosity coefficient of the fluid decreases due to the rise, the decrease in torque is suppressed and the decrease in transmitted torque is prevented.

In addition, the compression coil spring responds to the temperature rise of the fluid and automatically adjusts the spacing between the discs to the optimum spacing, so the torque fluctuation rate during driving is small and stable, and the compression coil spring shortens at the desired temperature. Also, the spacer maintains a constant distance between the driving disk and the driven disk and prevents mutual interference, so there is no chance that they will slide and wear out, or that they will generate heat and cause the temperature of the fluid to rise abnormally. Prevented.

F. Embodiment An embodiment of the fluid coupling according to the present invention will be described below based on the drawings.

Example 1 The fluid coupling shown in Figures 1a, b and 2 is as follows:
A casing consisting of a cylindrical body 1, side plates 2 and 3 disposed on both end faces of the body, an output shaft connecting portion 4, an input shaft 5, four drive disks 6 attached to the input shaft 5, and a casing. It is composed of five driven disks 7 and four steel balls 8 attached to the inner peripheral surface.

At both ends of the body 1, there are 8 at equal intervals in the radial direction.
Bolt holes 9 are drilled at the locations, and splines 10 are carved all around the inner cylindrical surface.

On the input shaft side, a disc-shaped side plate 2 and a stepped hole 12 through which the input shaft 5 is inserted are bored in the center part, and an oil seal 13 is fitted into the stepped part of the stepped hole 12. Ru. Further, the body portion 1 is attached to the outer peripheral portion of the side plate 2.
A bolt hole 14 is bored at a position corresponding to the bolt hole 9.

A tapered surface 11 is provided on the inner side near the outer periphery of the side plate 3 to generate a pressing force in the axial direction by utilizing centrifugal force on a steel ball 8 as a pressing member, which will be described later. moves toward the outer circumference, and taper surface 1
Applying a pressing force to the driven disk 7 along 1,
It is configured to reduce the overall distance between the driven disks 7 and increase torque transmission efficiency.

Further, the side plate 3 has a disk shape with an output shaft connecting portion 4 protruding from the center portion, and the body portion 1
A bolt hole 15 is bored at a position corresponding to the bolt hole 9.

In addition, the inner surface of the side plate 3 has steel ball storage areas 1 surrounded by ribs on three sides at four locations in the radial direction.
6 is provided on the tapered surface 11 with the open side of the ribs facing each other. Further, oil plug holes 17 are formed at two locations on the outer periphery of the side plate 3, and oil plugs are screwed into the holes 17. In addition, the output shaft connecting portion 4 includes a mounting hole 18 into which a connecting shaft of a driven object is inserted, and a key groove 1.
A set screw hole 20 is formed in the mounting hole 18 to maintain the axial position of the driven object with respect to the connecting shaft, and a set screw is screwed into the set screw hole 20. . A stop plate 21 is fitted into the bottom of the mounting hole 18 to prevent silicone oil sealed in the casing from leaking out. The body portion 1, side plates 2, and side plates 3 are integrally joined by eight tightening bolts and tightening nuts at bolt holes 9, 14, and 15 as shown in the figure.

The driven disk 7 is donut-shaped and has a spline 22 carved on its outer periphery, which engages with a spline 10 formed on the body 1 of the casing, making it possible to move in the axial direction. Between each of the driven disks 7, spring tubes 23 as cylindrical spacers serving as stoppers are fitted at four locations on the outer periphery at approximately equal intervals. The spring tube 23 is made of a shape memory alloy made of a shape memory alloy that has been heat treated to harden at a predetermined temperature so as to spread out the space between each drive disk 7. A compression coil spring 24 is arranged. This compression coil spring 24 is connected to the spring tube 23
The discs are inserted into the discs to prevent deformation due to fluid pressure, and at the time of start-up, an outward pressing force in the axial direction acts against the pressing force of the steel balls 8 to maintain an equal distance between each driven disk 7. It is configured as follows.

Also, this compression coil spring 24 has a natural length of 3.6 mm at temperatures below 18°C, but a natural length of 2.8 mm at temperatures above 18°C.
The axial length of one side of the spring cylinder 23 is 3.1 mm, which is compressed to 2.5 mm, so that the distance between the driven discs 7 is 4.1 mm at startup.
The distance from the drive disk 6 is uniformly shortened to 0.5 mm. Therefore, since the torque transmitted to the output shaft 4 is inversely proportional to the distance between the driving disk 6 and the driven disk 7, even if the viscosity coefficient of silicone oil decreases due to temperature rise, the shortening of the distance will cause A decrease in torque is suppressed and a decrease in transmitted torque is prevented.

The input shaft 5 has a cylindrical shape and has a mounting hole 25 for mounting an output shaft (not shown) of a driving power source having a spline carved therein, and a hole 25 at the back of the mounting hole 25 that fits into the spline of the output shaft. Spline 26 to match
is engraved. Further, a spline 27 is carved on the outer surface of the input shaft 5, and a stop plate 28 is coupled to the end surface. Near both ends of the spline 27, there is a retaining ring groove 2 with a constant width around the entire circumference.
9 are respectively engraved, and as will be described later, after the drive disk 6 is fitted, a retaining ring is fitted to prevent the drive disk from coming off.

The drive disk 6 is carved with a spline 30 that fits with the spline 27 at the center, and oil holes 31 are drilled on the outside of the spline 30 to allow silicone oil to flow at multiple locations on the same circumference. There is.

The steel ball 8 as a pressing member is a normal steel ball, and is stored in a space defined by a steel ball storage portion 16 provided on the inner surface of the side plate 3 and a driven disk 7.

To assemble the above components, first, the side plate 2 is placed on a table with its inner surface facing up, and the body 1 is placed thereon with the bolt holes 9 and 14 aligned concentrically. Further, an input shaft 5 fitted with a retaining ring groove 29 on the retaining plate 28 side is installed in the center, and one steel ball 8 is placed in each space divided by the steel ball storage section 16 and the driven disk 7. . Thereafter, the splines 22 of the driven disk 7 and the splines 30 of the drive disk 6 are fitted to the splines 10 of the body 1 and the splines 27 of the input shaft 5, respectively, and are fitted alternately, and at the same time, the splines 22 of the driven disk 7 and the splines 30 of the drive disk 6 A spring tube 23 as a spacer is fixed to the spring tube 23 with adhesive, and a compression coil spring 24 is housed inside the spring tube 23. After fitting the last driven disk 7, attach a retaining ring to the input shaft 5, and attach the side plate 2.
and then connect the whole thing together with a tightening nut. After this, a predetermined amount of silicone oil is injected from the oil plug hole 17, and the oil plug is screwed in.
In this state, the driving disk 6 and the driven disk 7
The average disk spacing at rest is set somewhat larger.

To the fluid coupling thus assembled, the shaft of the motor serving as the drive power source is attached to the attachment hole of the input shaft 5, and the traveling wheel shaft of a crane, for example, is attached to the output shaft connection portion 4.

When stopped, the steel balls 11 are stored in the steel ball storage part 16, but when started, the driven discs 7 are gradually pressed by centrifugal force according to the rotational speed of the side plate, and the distance between the driven discs 7 is reduced. This rotation raises the temperature of the silicone oil and lowers its viscosity, but when the temperature of the silicone oil reaches 18°C, the compression coil spring 24 hardens and the spring length is shortened, as described above. ,
Applying a tensile force to the driven discs 7, the distance between the driven discs 7 becomes approximately the same as the axial length of the spring cylinder 23,
As a result, the distance between the driven disk 7 and the driven disk 6 is only 0.5 mm, which prevents the transmission torque from decreasing, and also keeps the distance between the driven disk 6 and the driven disk 7 constant so that they do not interfere with each other. This prevents both from sliding and wearing out, and from generating heat and causing the temperature of the fluid to rise abnormally.

After the driving is finished, the temperature of the silicone oil drops again, the compression coil spring 24 again generates a spring force outward, and the distance between the driven disks 7 increases.

A test was conducted using this fluid coupling, and it was found that when the compression coil spring 24 subjected to shape memory heat treatment is not inserted between the driven disks 7, the fluctuation rate of torque transmission during driving is ±20% from 0 to 18°C, 18 ±50 at ~50℃
%, but when the compression coil spring 24 is inserted, it becomes ±20% at 18 to 50°C, and since the spacing between the discs is automatically adjusted in response to the temperature rise of the fluid, the torque fluctuation rate during driving is reduced. It is small, stable, and can be used over a wide range of areas.

Here, an example of attaching a spring tube as a spacer, which is different from the first embodiment, will be shown below.

Embodiment 2 Figures 3a, b, and 4 show a second embodiment, and the configurations of the casing, output shaft connection part 4, input shaft 5, drive disk 6, and steel ball 8 are as follows. Since this is the same as the first embodiment described above, repeated explanation will be omitted.

Each of the driven disks 7a arranged second from both outer sides has bored holes 32 into which the spring tubes 23a are inserted, which are formed at four locations near the outer periphery at approximately equal intervals.
A spring tube 23a is inserted into this drilled hole 32. The spring cylinder 23a is partitioned at the center, and a compression coil spring 24 made of a shape memory alloy that has been subjected to memory heat treatment to harden at a predetermined temperature is disposed in the left and right cylinders so as to spread the space between the driven disks. ing. The compression coil spring 24 is configured to exert an axially outward pressing force against the pressing force of the steel ball 8 at the time of starting, thereby maintaining the distance between the driven disks.

In this embodiment, the distance between the driven disks is reduced by the same effect as in the first embodiment.

In Examples 1 and 2, only compression coil springs with shape memory hardening are used, but a combination spring with two-way operating characteristics in which a compression coil spring with shape memory hardening is combined with a normal coil spring as a bias load is used. Examples used are shown below.

Example 3 Similar to the second example, explanations of the configurations of the casing, output shaft connecting portion 4, input shaft 5, drive disk 6, and steel ball 8 will be omitted.

Spring tube 23 as a spacer with one end closed
Compression coil spring 2 with shape memory hardening in b
4a and a normal compression coil spring 24b are connected by a connecting member 33 and used as a combination spring (see FIGS. 5a and 6).

When the combination spring is expanded, one end of the spring pops out from the spring tube 23b due to the spring force of the compression coil spring 24a having shape memory hardening and the normal compression coil spring 24b, thereby maintaining the spring length.

When the combination spring contracts, the spring length of the compression coil spring 24a having shape memory hardening is shortened,
The entire length of the spring can be accommodated within the spring tube 23b.

A pair of these combination springs are arranged symmetrically with respect to the input shaft 5, and two hollow portions 34 are formed in the driven disk located at the center, and two hollow portions are formed in the two driven disks 7 located on both sides. 34, and four spring cylinder insertion holes are formed at approximately equal intervals on the corresponding outer periphery of each driven disk 7 arranged second from both outer sides, and spring cylinder insertion holes are formed in the spring cylinder insertion holes. 23b are attached with the closed sides facing the hollow portion 34, respectively.

When this fluid joint is driven and the temperature of the fluid rises, the compression coil spring 24 with shape memory hardening
a hardens and contracts, and the normal compression coil spring 24b is fully extended accordingly, but the spring length of the combined spring as a whole is shortened, so a tensile force is applied between each driven disk, and the distance between each driven disk is reduced. Shrink.

After the fluid coupling stops, the fluid temperature gradually decreases.
The compression coil spring 24a having shape memory hardening recovers its spring force, the spring length of the combined spring as a whole increases, and the spacing between each driven disk 7 returns to its original state.

In addition, the spring tube is not just a cylindrical shape, but a stepped spring tube 23c having a large diameter and a small diameter on the same axis, as shown in FIGS. 7a, b, and 8. By inserting the spring tubes and fixing them with adhesive or the like, the protrusion distances of all the spring tubes 23c can be reliably made uniform without requiring detailed measurements.

In the second and third embodiments, as shown in FIG. 9, a notch may be formed in the driven disk 7 from its periphery, and the spring tube 23a may be fixed thereto by adhesive, welding, or the like.

In addition, the magnitude of hysteresis, which is a problem when using a combination spring as described above, is not a problem as long as the temperature of the fluid has completely cooled down before restarting. , there will be no problem if one with small hysteresis is used.

Furthermore, in this example, the steel balls are used to improve the torque transmission efficiency during rotation, and the compression coil spring made of a shape memory alloy is used to prevent the transmission torque from decreasing due to temperature rise. It is not necessary to insert them between all adjacent driven disks, and may be omitted as long as the distance between each disk can be maintained evenly. Alternatively, it may be configured only with a compression coil spring made of a shape memory alloy without using steel balls.
If the stroke of the compression coil spring is set long and the distance between the disks is varied by pressing the driven disks at both ends with separate positioning springs, it is possible to adjust the torque at startup. becomes.

Effects As detailed above, according to the present invention, even if the temperature of the fluid increases due to an increase in the rotational speed of the input shaft and the viscosity coefficient decreases, the shape memory The alloy compression coil spring responds to the temperature of the fluid and automatically adjusts the spacing between the discs to an even and optimal spacing at the desired temperature, which prevents a drop in transmitted torque and reduces the rate of torque fluctuation during driving. It is stable and can be used in a wide temperature range.

Furthermore, even if the compression coil spring is shortened at a desired temperature and the distance between the driven disks is shortened, since the protruding thickness of the spacer is greater than the thickness of the driving disk, mutual interference between the driving disk and the driven disk is prevented. Since the compression coil spring is inserted and protected by the spacer of the cylindrical body, deformation due to fluid pressure is prevented and the distance between the two disks is maintained constant, and the distance between the driving disk and the driven disk is thereby maintained. This prevents the fluid from sliding and wearing out, or from generating heat and causing the temperature of the fluid to rise abnormally.

Furthermore, by appropriately changing the hardening temperature and coil length of shape memory alloy compression coil springs and using them in combination with regular coil springs, it is possible to widely apply them to fluid couplings for various purposes.
Its practical value is great.

[Brief explanation of the drawing]

The drawings show a fluid coupling according to the present invention, and FIG. 1a is a cross-sectional view taken along line A-A in FIG.
Figure a is an enlarged explanatory view of the insertion part between the compression coil spring and the spring tube, Figure 2 is a left side view of Embodiment 1, Figure 3 is a
is a sectional view taken along line B-B in FIG. 4, FIG. 3b is an enlarged explanatory view of the compression coil spring and spring tube insertion part in FIG. Figure a is a sectional view taken along the Y-O-X line in Figure 6, and Figure 5 b is a cross-sectional view of the fifth
Figure a is an enlarged explanatory view of the insertion part between the compression coil spring and the spring tube, Figure 6 is a left side view of Embodiment 3, Figure 7 a
is a sectional view taken along the Y'-O'-X' line in Fig. 8, Fig. 7b
is an enlarged explanatory view of the insertion part between the coil spring and spring tube in FIG. 7a, FIG. 8 is a left side view of a modified example of coil spring installation, FIG. 9 is an explanatory view of a modified example of spring tube installation, and FIG. 10 is an explanatory diagram of a conventional example. 4... Output shaft, 5... Input shaft, 6... Drive disk, 7, 7a... Driven disk, 8... Steel ball, 23, 23a, 23b, 23c...
Spring tube, 24, 24a...compression coil spring.

Claims (1)

[Scope of utility model registration request] An input shaft connected to a driving power source, a sealed rotary casing that surrounds the input shaft so as to be relatively rotatable and is filled with a viscous fluid, and a rotary casing provided coaxially with the input shaft on the output side of the casing. A plurality of drive disks are provided on the outer peripheral surface of the input shaft so as to be slidable in the axial direction at appropriate intervals, and the plurality of drive disks are provided on the inner peripheral surface of the casing. In a fluid coupling in which donut-shaped driven disks are slidably provided in the axial direction and alternately overlap each other with a slight distance between each other, the distance between adjacent driven disks is normally equal to the distance between adjacent driven disks. a compression coil spring made of a shape memory alloy that maintains the spring length at a desired temperature and shortens the distance between the driven disks, and a compression coil spring that is fixed to the driven disk and has a protruding thickness from the plate surface of the driven disk. 1. A fluid coupling comprising: a cylindrical spacer whose thickness is greater than the thickness of the drive disk and into which the compression coil spring can be inserted.